The present invention is directed to winding tubes, and more particularly to a predominantly paper, reusable winding tube in which the fibers or filaments are more easily removed from the starting groove which carries the waste bunch once the package has been emptied.
In conventional automatic winding operations, yarn is wound onto a cylindrical laminated paper tube. One end of the paper tube includes a peripheral starting groove cut into the surface thereof (U.S. Pat. No. 3,103,305). In some systems, the starting groove is divided into two arcuate portions. The greater arcuate portion (approximately 270.degree.) is wider and referred to as the lead-in portion, while the smaller (approximately 90.degree.) arcuate portion (locking portion) is narrower and locks one or more of the initial strands of yarn therein during the initial few turns of the automatic winding operation. In other systems, particularly those in which fine denier yarn is being wound, the starting roove has a single configuration that is constant in cross-sectional size and shape around the entire periphery. It is also possible that the starting groove extends only partially around the periphery of the tube to latch the initial wraps of the transfer tail. These strands and the next several wraps (approximately 100) are hereinafter and commonly referred to as the "waste bunch." The completed yarn package is removed from the winding machine, and stored or shipped for further processing. During further processing, the yarn is then removed from the yarn carrier.
When the yarn is removed from the package, the last few strands of the waste bunch remain wedged in the lead-in and locking portions of the starting groove. Because of the construction of conventional paper tubes, it is very difficult to remove these remaining strands of fibrous or filamentary material. Previous attempts to remove these strands have included vacuum stripping, cutting of the strands, or a combination of both. Neither technique is satisfactory, because vacuum stripping simply does not remove all the fibrous or filamentary material. Cutting the waste bunch of these types of paper tubes generally results in damage to the surface of the paper tube making it unsuitable for further use. Such damage occurs when the laminates of the paper tube are nicked, cut, or otherwise interrupted. Use of a damaged tube at high speeds then tends to result in delamination.
As a result, conventional paper winding tubes are generally not reusable. There have been some attempts to reuse the tubes at least once by providing the starting grooves at each end of the tube, so that the tube can be reused at least once. However, often the tube is otherwise damaged during the automatic doffing and emplacement operations which substantially eliminates the reuse of the paper tubes. Conventional paper tubes are relatively expensive (25.cent. to $1.00 apiece) and hundreds of thousands per year are used by typical yarn manufacturers. Thus the cost of non-reusable yarn carriers is extremely high.
Merely the replacement of paper tubes with a stronger material such as a polymeric material or aluminum is not an obvious solution. First, the starting groove cannot satisfactorily be molded or machined in the wall of a polymeric or metallic tube. Secondly, merely a change of material does not solve the problems created by the necessity to clean the waste bunch groove, as it is still not easy to vacuum the groove, and utilizing a knife will still damage the surface of the tube so that it cannot be reused. While the use of polymeric material or metallic material such as aluminum is a first step toward an improved tube, it has been found that some improved technique for cleaning of the starting groove must be provided in order to achieve a reusable winding tube.
Examples in the prior art of separable yarn carriers are illustrated in the Chaffin U.S. Patent No. 1,991,880; Moss U.S. Pat. No. 2,837,297; and Underwood U.S. Pat. No. 3,971,526. However, none of these yarn carriers are for high speed automatic winding operations or solve the problems attendant to the removal of residual fibers and filaments from a starting groove.
In our copending Ser. No. 200,939 filed May 31, 1988, now U.S. Pat. No. 4,834,314, and Ser. No. 321,038, filed Mar. 9, 1989, the tube is formed entirely of a polymeric or metallic material in two separable parts, i.e. the main hollow tube portion and a removable end cap. A starting groove is formed between the abutting end walls of the end cap and hollow tube to receive the waste bunch during the automatic winding operation. After the yarn package is emptied the end cap is removed or partially removed from the hollow tube portion, the fibers or filaments vacuumed or stripped away, and the end cap replaced. The yarn carrier is then ready for reuse.
A French Patent No. 2,463,088 to Viscosuisse, S.A. shows a somewhat related concept in which a paper tube has a friction fit (apparently plastic) slip-on ring releasably attached to the end thereof. The slip-on ring has resilient fingers that fit inside the paper tube and hold the two components in assembled relation. The confronting walls of the slip-on ring and paper tube are not peculiarly designed or of a satisfactorily rigid material to form a starting groove of of constant size and shape.
While the separable yarn carriers illustrated and described in our copending applications identified hereinabove have desirable characteristics and suggest improvements that might solve the groove cleaning problem, they also do not address certain problems and may not be acceptable as described in some existing installations. The all polymeric or metallic tube represents a significant change from the industry accepted paper tube. Obviously, the dies and/or molds for such an approach are very expensive. Further, the industry strongly prefers paper tubes for two reasons. First, from the standpoint of safety, if a paper tube fails at high speeds, it merely delaminates and no damage to equipment or personnel occurs. However, if a polymeric or metallic tube should fail, a large number of brittle pieces are released which could be dangerous to personnel or equipment. Secondly, some yarn carriers are surface driven by engaging the surface of the latch end and/or the take-off end with drive means. The drive wheels are designed to be compatible with paper and tend to scar conventional polymeric and other surfaces with a result that they may become prematured, worn and unusable.
In the broadest aspect of the present invention, it is desired to accomplish the cleaning of the starting groove by making the end cap removable, yet address the problems attendant to all polymerics or metallic tubes set forth hereinabove. A hollow paper tube and separable end cap are joined to form a starting groove at a rigid, incompressible interface therebetween. The end of the hollow paper tube is provided with a rigid insert of polymeric or metallic material. Some end caps are all polymeric, while those end caps which are engaged by drive wheels are either paper with a rigid insert or are polymeric with some type of wear-resistant surface. The inserts include mating surface configurations which form the confronting walls of the grooves and selectively effect a secure attachment of the end cap to the tube, yet allow for selective separation of the end cap and hollow tube to remove loose fibers from the starting groove. Since the hollow tube of the resulting yarn carrier is predominantly paper, and the only rigid material is the relatively small, underlying inserts which are supported peripherally, the safety concerns of the industry are fulfilled and the desirable paper surface is maintained.
In its more specific aspects the reusable winding carrier of the present invention includes a hollow, predominantly paper, tube having an outer, substantially cylindrical surface adapted to carry a filamentary or fibrous yarn thereon. The end cap includes an outer substantially cylindrical surface generally of the same radius (or in some case slightly greaster radius) as the outer surface of the hollow tube. In some embodiments, the end cap is provided with a paper or wear-resistant surface. In other embodiments where the drive wheels or bale engages only the opposite end of the winding tube during start-up, the end caps may be all polymeric. The end cap and hollow tube are each provided with mating threads or other attachment means for releasably mounting the end cap on at least one end of the hollow tube. It is possible that both ends of the hollow tube may include releasable end caps of the type described to further increase the life expectancy of the winding tube.
A starting groove is formed between the confronting walls of the hollow tube and end cap inserts which starting groove extends around a portion or all of the entire periphery of the yarn carrier. For some winding operations, the starting groove is formed with a relatively narrow locking portion extending around a minor portion (preferably approximately 90.degree.) of the periphery of the tube and a relatively wider lead-in portion extending around the remaining portion of the periphery. The lead-in portion guides the first few turns of the waste bunch into the locking portion. The wider and narrower portions into of the starting groove are formed by molding recesses into or chamfering one or both abutting ends of the hollow tube and/or end cap during the fabrication of the components. In other winding operations, notably for the winding of finer denier yarns, the lead-in portion is unnecessary. For such operations the starting groove between the end cap and hollow tube has a constant configuration throughout.
Since the confronting walls of the end cap and hollow tube which engage each other are both of a rigid or substantially incompressible material such as a polymeric or lightweight metallic material, the configuration of the groove may be reliably formed and maintained even after repeated usage. When the operator torques the end cap against the hollow tube, the angle of the starting groove is formed and maintained. As a result, yarn cannot slip down between the engaged confronting walls. Because the material is incompressible, subsequent loosening does not occur. Further, humidity is less likely to change the groove dimensions of a rigid, incompressible material whereas paper is very sensitive to humidity. The material of the end cap and hollow tube which form the confronting walls of the groove should be the same rigid, incompressible material, because it is too expensive to form, grind and burnish a separate material. The rigid walls surrounding the groove will maintain the proper angle therebetween even after repeated usage and regardless of humidity changes. Thus, the rigid polymeric or lightweight metallic material surrounding the latching groove can be machined or molded and retain the precise geometry required on repeated latching to retain long term stability and reliability.
It is therefore an object of the present invention to provide predominantly paper yarn carriers which are made reusable by facilitating the cleaning of the starting groove.
It is another object of the present invention to provide a predominantly paper yarn carrier of the type described in which an end cap is releasably attached to the main body portion and forms a starting groove therebetween.
It is another object of the present invention to provide a yarn carrier of the type described in which the outer surface of at least the hollow tube is paper and the attachment means for joining the two are polymeric or metallic inserts which underlie the paper portion.